1. Field of the Invention
The present invention relates generally to spraying devices for spraying liquids from a container, and, more particularly, to hand held spraying devices capable of spraying at least two different fluids simultaneously through a single spray head.
2. Brief Description of the Prior Art
There are numerous hand held spray devices known in the prior art. Most of such spray devices are designed to deliver a single fluid such as a solution of water and a detergent. Also known in the prior art are various hand held spray devices which are designed to deliver mixtures of two or more liquids through a spray head. One such device is taught in U.S. Pat. No. 5,009,342 to Lawrence, et al. The device of Lawrence, et al. utilizes a valve assembly mounted between the compartments containing the two different liquids and the spray pump assembly. The valve assembly includes inner and outer control valve members for controlling the connection of the inlet to the outlet. The control valve members are rotatable relative to one another which allows the size of the inlets to be variable so as to vary the ratio of the two liquids being dispensed.
U.S. Pat. No. 4,355,739 to Vierkotter teaches a container spray head assembly wherein suction is taken from two separate chambers allowing the delivery of the mixture of two liquids. A lipped valve is provided at the top of each take up tube to each chamber. Pumping action of the spray head combines the two liquids in a mixing chamber and ejects the mixed liquid from the spray head. A rotating cylinder is provided downstream of one of the lipped valves, the rotating cylinder having openings therein. Rotation of the cylinder allows for variation in the mixing ratio between the two liquids.
U.S. Pat. No. 3,786,963 to Metzler, III teaches a spray head assembly capable of dispensing mixed components drawn from two separate reservoirs. Two dip tubes are provided which have ball check valve prior to entry into the mixing chamber.
U.S. Pat. No. 5,152,461 to Proctor teaches yet another hand operated spray device capable of drawing fluids from two separate reservoirs. Proctor utilizes a very specialized spray head which includes threaded connections for two separate bottles. The dip tubes extend all the way to a point immediately adjacent to the spray nozzle where a diaphragm is provided which apparently serves as a flapper type check valve. Means are provided to pinch one or the other of the dip tubes to thereby vary the ratio of the liquids being drawn from the reservoirs.
Generally speaking, each of the spray heads taught in the prior art capable of drawing suction from two different reservoirs are relatively complicated requiring a redesign of the typical one fluid source spray head resulting in an overall lengthening of the spray head to allow for the inclusion of additional elements. Further, although the potential problem of syphoning created by a dual reservoir device has been recognized by Vierkotter, nothing in the prior art teaches a means for automatically preventing syphoning. Further, the present invention automatically prevents syphoning even when the device is stored in a non-vertical position.